Case report: Levodopa challenge test is important in identifying dopamine-induced freezing of gait in patient with Parkinson's disease.

Introduction: Freezing of gait (FOG) is a disabling and heterogeneous symptom in patients with Parkinson's disease (PD). Among them, dopamine-induced FOG is rare and difficult to identify. The treatment of dopamine-induced FOG is complex. Case presentation: We herein presented a case of PD patient who complicated with refractory FOG. It was identified as dopamine-induced FOG during levodopa challenge test. Her symptoms were alleviated after we reduced the total equivalent dosage of levodopa. Conclusion: Our report emphasizes the importance of levodopa challenge test in identifying different types of FOG, which is very important for further adjusting treatment.

Metabolomics-Based Study of the Protective Effect of 4-Hydroxybenzyl Alcohol on Ischemic Astrocytes.

Ischemic stroke is a common and dangerous disease in clinical practice. Astrocytes (ASs) are essential for maintaining the metabolic balance of the affected regions during the disease process. 4-Hydroxybenzyl alcohol (4HBA) from Gastrodia elata Bl. has potential neuroprotective properties due to its ability to cross the blood-brain barrier. In an in vitro experiment, we replicated the oxygen-glucose deprivation/reoxygenation model, and used methyl thiazoly tertrazolium, flow cytometry, kits, and other technical means to clarify the protective effect of 4HBA on primary ASs. In in vivo experiments, the 2VO model was replicated, and immunofluorescence and immunohistochemistry techniques were used to clarify the protective effect of 4HBA on ASs and the maintenance of the blood-brain barrier. Differential metabolites and related pathways were screened and verified using metabolomics analysis and western blot. 4HBA noticeably amplified AS cell survival, reduced mitochondrial dysfunction, and mitigated oxidative stress. It demonstrated a protective effect on ASs in both environments and was instrumental in stabilizing the blood-brain barrier. Metabolomic data indicated that 4HBA regulated nucleic acid and glutathione metabolism, influencing purines, pyrimidines, and amino acids, and it activated the N-methyl-D-aspartate/p-cAMP-response element binding protein/brain-derived neurotrophic factor signaling pathway via N-methyl-D-aspartate R1/N-methyl-D-aspartate 2C receptors. Our findings suggest that 4HBA is a potent neuroprotective agent against ischemic stroke, enhancing AS cell survival and function while stabilizing the blood-brain barrier. The N-methyl-D-aspartate/p-cAMP-response element binding protein/brain-derived neurotrophic factor signaling pathway is activated by 4HBA.

Palmitoyltransferase ZDHHC3 is essential for the oncogenic activity of PML/RARα in acute promyelocytic leukemia.

The oncogenic fusion protein promyelocytic leukemia/retinoic acid receptor alpha (PML/RARα) is critical for acute promyelocytic leukemia (APL). PML/RARα initiates APL by blocking the differentiation and increasing the self-renewal of leukemic cells. The standard clinical therapies all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), which induce PML/RARα proteolysis, have dramatically improved the prognosis of APL patients. However, the emergence of mutations conferring resistance to ATRA and ATO has created challenges in the treatment of APL patients. Exploring pathways that modulate the oncogenic activity of PML/RARα could help develop novel therapeutic strategies for APL, particularly for drug-resistant APL. Herein, we demonstrated for the first time that palmitoylation of PML/RARα was a critical determinant of its oncogenic activity. PML/RARα palmitoylation was found to be catalyzed mainly by the palmitoyltransferase ZDHHC3. Mechanistically, ZDHHC3-mediated palmitoylation regulated the oncogenic transcriptional activity of PML/RARα and APL pathogenesis. The knockdown or overexpression of ZDHHC3 had respective effects on the expression of proliferation- and differentiation-related genes. Consistently, the depletion or inhibition of ZDHHC3 could significantly arrest the malignant progression of APL, particularly drug-resistant APL, whereas ZDHHC3 overexpression appeared to have a promoting effect on the malignant progression of APL. Thus, our study not only reveals palmitoylation as a novel regulatory mechanism that modulates PML/RARα oncogenic activity but also identifies ZDHHC3 as a potential therapeutic target for APL, including drug-resistant APL.

Healthy life expectancy with cardiovascular disease among Chinese rural population based on the prospective cohort study.

BACKGROUND: Limited research has explored the impact of cardiovascular disease (CVD) on healthy life expectancy (HLE) especially in resource-limited areas. This study aimed to investigate the association between CVD and HLE in Chinese rural population. METHODS: This study included 11,994 participants aged 45 years and older from the baseline and follow-up surveys of the Henan rural cohort study. Healthy status was measured via a Visual Analogue Scale. The multistate Markov model was applied to estimate the association between CVD and transitions in health, unhealthiness and death. Gender-specific total life expectancy, HLE and unhealthy life expectancy were calculated by the multistate life table method. RESULTS: During a mean follow-up time of 3.85 (3.84-3.86) years, there were 588 deaths recorded. For individuals with CVD, the risk of switching from health to unhealthiness status was increased by 71% [hazard ratio (HR) = 1.71, 95% CI: 1.42-2.07], the chance of recovery was reduced by 30% (HR = 0.70, 95% CI: 0.60-0.82). Men aged 45 years without CVD could gain an extra 7.08 (4.15-10.01) years of HLE and lose 4.00 (1.60-6.40) years of unhealthy life expectancy compared to their peers with CVD, respectively. The corresponding estimates among women were 8.62 (5.55-11.68) years and 5.82 (2.59-9.04) years, respectively. CONCLUSIONS: This study indicated that CVD was significantly associated with poorer health status and lower HLE among Chinese rural population. It is an important public health policy to adopt targeted measures to reduce the CVD burden and enhance the quality of life and HLE in resource-limited areas.

Single-pixel positron beam diagnosis via compressive sampling.

The morphology is a crucial indicator for diagnosing a low-energy, low-brightness particle beam. However, conventional positron beam diagnosis, based on the pixel scanning principle, is limited by physical constraints, such as the resolution of detector pixels. Here, we have presented a novel slow positron diagnosis method using compressive sampling. With a 100 × 100 pixel-sized mask, for example, the positron beam morphology can be significantly reconstructed with a peak signal-to-noise ratio of ∼40 dB, even at half the sampling rate compared to pixel scanning. It explores a promising approach for positron beam diagnosis with an ultra-high resolution and fast sampling rates.

Shionone Inhibits Glomerular Fibirosis by Suppressing NLRP3 Related Inflammasome though SESN2-NRF2/ HO-1 Pathway.

Background: Diabetic nephropathy (DN) is the most common and serious complication of diabetes mellitus. Shionone (SH), an important triterpenoid compound in the root extract of Aster, might exert a protective effect in DN mice and high glucose cultivated glomerular podocytes. The current study aimed to unravel the underlying mechanism by which SH mitigates DN. We postulate that SH stimulates the expression of sestrin-2 (SESN2), a pivotal stress-inducible protein in the anti-inflammasome machinery. Methods: We utilized high-fat diet combined with streptozotocin (55 mg/kg intraperitoneal) for DN mice model, and high glucose (30 mM, 48 hours) cultured glomerular podocytes for DN cell model to evaluate the effect of SH. We also preformed experimentation on SESN2 deficiency models (SESN2 knockout mice and SESN2 siRNA in cells) to further prove our hypothesis. Results: The results demonstrated that SH effectively suppressed glomerular fibrosis, induced adenosine monophosphate-activated protein kinase (AMPK) phosphorylation, and inhibited NLR family pyrin domain containing 3 (NLRP3) activation. Furthermore, our findings revealed that SH exerted its anti-inflammatory effect through Sesn2-dependent nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation and subsequent activation of its downstream target heme oxygenase-1 (HO-1). Conclusion: In summary, our findings suggest that SH serves as a promising therapeutic agent for the treatment of DN-related glomerular fibrosis. SH enhances the expression of SESN2, attenuates α-smooth muscle actin accumulation, and suppresses NLRP3-related inflammation through the Nrf2/HO-1 signaling pathway.

Ganoderma lucidum polysaccharides reduce the severity of acute liver injury by improving the diversity and function of the gut microbiota.

Acute liver injury (ALI) is an abnormal liver function caused by oxidative stress, inflammation and other mechanisms.The interaction between intestine and liver plays an important role in ALI, and natural polysaccharides can participate in the regulation of ALI by regulating the composition of intestinal flora. In this study, Ganoderma lucidum polysaccharide was used as the research object, and ICR mice were used to construct an acute liver injury model induced by carbon tetrachloride (CCl4). 16S rRNA sequencing technology was used to analyze the flora structure abundance and detect the changes of intestinal flora. The effective reading of 8 samples was obtained by 16S rRNA sequencing technology, and a total of 1233 samples were obtained. The results of alpha diversity analysis showed that the sequencing depth was sufficient, the abundance of species in the samples was high and the distribution was uniform, and the sequencing data of the samples was reasonable. Nine species with significant differences were screened out by abundence analysis of intestinal flora structure at genus level. Beta diversity analysis showed that species composition was different between the model group and the treatment group. Ganoderma lucidum polysaccharide can maintain the integrity of mucosal barrier by promoting the proliferation of intestinal epithelial cells and anti-oxidative stress injury, thereby improving the intestinal mucosal inflammation of mice, regulating intestinal flora, and effectively alleviating CCl4-induced acute liver injury.

Linking morphology, genome, and metabolic activity of uncultured magnetotactic Nitrospirota at the single-cell level.

BACKGROUND: Magnetotactic bacteria (MTB) are a unique group of microorganisms that sense and navigate through the geomagnetic field by biomineralizing magnetic nanoparticles. MTB from the phylum Nitrospirota (previously known as Nitrospirae) thrive in diverse aquatic ecosystems. They are of great interest due to their production of hundreds of magnetite (Fe3O4) magnetosome nanoparticles per cell, which far exceeds that of other MTB. The morphological, phylogenetic, and genomic diversity of Nitrospirota MTB have been extensively studied. However, the metabolism and ecophysiology of Nitrospirota MTB are largely unknown due to the lack of cultivation techniques. METHODS: Here, we established a method to link the morphological, genomic, and metabolic investigations of an uncultured Nitrospirota MTB population (named LHC-1) at the single-cell level using nanoscale secondary-ion mass spectrometry (NanoSIMS) in combination with rRNA-based in situ hybridization and target-specific mini-metagenomics. RESULTS: We magnetically separated LHC-1 from a freshwater lake and reconstructed the draft genome of LHC-1 using genome-resolved mini-metagenomics. We found that 10 LHC-1 cells were sufficient as a template to obtain a high-quality draft genome. Genomic analysis revealed that LHC-1 has the potential for CO2 fixation and NO3- reduction, which was further characterized at the single-cell level by combining stable-isotope incubations and NanoSIMS analyses over time. Additionally, the NanoSIMS results revealed specific element distributions in LHC-1, and that the heterogeneity of CO2 and NO3- metabolisms among different LHC-1 cells increased with incubation time. CONCLUSIONS: To our knowledge, this study provides the first metabolic measurements of individual Nitrospirota MTB cells to decipher their ecophysiological traits. The procedure constructed in this study provides a promising strategy to simultaneously investigate the morphology, genome, and ecophysiology of uncultured microbes in natural environments. Video Abstract.

[Analysis of the therapeutic effect of trochanteric flip osteotomy combined with Kocher-Langenbeck approach for high acetabular posterior wall fracture].

OBJECTIVE: Evaluation of the clinical efficacy of f trochanteric flip osteotomy combined with Kocher-Langenbeck approach for high acetabular posterior wall fracture. METHODS: Between January 2020 and December 2022, 20 patients with high acetabular posterior wall fractures were retrospectively analyzed, including 12 males and 8 females, aged 18 to 75 years old. They were divided into two groups according to the different surgical methods. Ten patients were treated with greater trochanteric osteotomy combined with Kocher-Langenbeck approach as the observation group, including 5 males and 5 females, aged from 18 to 75 years old. Ten patients were treated with Kocher-Langenbeck approach alone as the control group, including 7 males and 3 females, aged from 18 to 71 years old. Matta reduction criteria were used to evaluate the reduction quality of the two groups, and Harris score was used to compare the hip function of the two groups at the latest follow-up. The operation time, blood loss and postoperative complications of the two groups were analyzed. RESULTS: All patients were followed up for 10 to 24 months. According to the Matta fracture reduction quality evaluation criteria, the observation group achieved anatomical reduction in 6 cases, satisfactory reduction in 3 cases, and unsatisfactory reduction in 1 case, while the control group only achieved anatomical reduction in 3 cases, satisfactory reduction in 3 cases, and unsatisfactory reduction in 4 cases. At the final follow-up, the Harris hip score ranged from 71.4 to 96.6 in the observation group and 65.3 to 94.5 in the control group. According to the results of Harris score. The hip joint function of the observation group was excellent in 6 cases, good in 3 cases, and fair in 1 case. The hip joint function of the control group was excellent in 2 cases, good in 3 cases, fair in 3 cases, and poor in 2 cases. In the observation group, the intraoperative blood loss ranged from 300 to 700 ml, and the operation duration ranged from 120 to 180 min;in the control group, the intraoperative blood loss ranged from 300 to 650 ml, and the operation duration ranged from 100 to 180 min. Complications in the observation group included 1 case of traumatic arthritis and 1 case of heterotopic ossification, while complications in the control group included 3 cases of traumatic arthritis, 3 cases of heterotopic ossification and 1 case of hip abduction weakness. CONCLUSION: Trochanteric flip osteotomy combined with the Kocher-Langenbeck approach significantly improved anatomical fracture reduction rates, enhanced excellent and good hip joint function outcomes, and reduced surgical complication incidence compared to the Kocher-Langenbeck approach alone. Clinical application of this combined approach is promising, although larger studies are needed for further validation.

Mitochondrial dysfunction in diabetic nephropathy: insights and therapeutic avenues from traditional Chinese medicine.

Diabetic nephropathy (DN) is a microvascular complication of diabetes mellitus. The progressive damage to glomeruli, tubules, and interstitium in the kidneys can lead to the development of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Most of the energy we need comes from mitochondria. Mitochondria are best known as the sites for production of respiratory ATP and are essential for eukaryotic life. The pathogenesis of DN involves a variety of factors, such as altered haemodynamics, oxidative stress, and inflammation, and studies from animal models suggest that mitochondrial dysfunction plays an important role in the development of DN. Traditional Chinese medicine (TCM) has a history of more than 2,500 years and has rich experience and remarkable efficacy in the treatment of DN. Recent studies have found that TCM may have great potential in regulating mitochondrial dysfunction in the treatment of DN. This review will elucidate the main causes of mitochondrial dysfunction and the relationship with DN, and explore in depth the potential mechanisms of TCM to protect the kidney by improving mitochondrial dysfunction. Current pharmacological treatments for patients with DN do not prevent the inevitable progression to ESRD. With the rich variety of Chinese herbs, TCM is expected to be the most promising candidate for the treatment of DN as we continue to learn more about the mechanisms of DN and incorporate the current advances in extraction techniques.

Atorvastatin ameliorated myocardial fibrosis by inhibiting oxidative stress and modulating macrophage polarization in diabetic cardiomyopathy.

In this editorial, we commented on the article published in the recent issue of the World Journal of Diabetes. Diabetic cardiomyopathy (DCM) is characterized by myocardial fibrosis, ventricular hypertrophy and diastolic dysfunction in diabetic patients, which can cause heart failure and threaten the life of patients. The pathogenesis of DCM has not been fully clarified, and it may involve oxidative stress, inflammatory stimulation, apoptosis, and autophagy. There is lack of effective therapies for DCM in the clinical practice. Statins have been widely used in the clinical practice for years mainly to reduce cholesterol and stabilize arterial plaques, and exhibit definite cardiovascular protective effects. Studies have shown that statins also have anti-inflammatory and antioxidant effects. We were particularly concerned about the recent findings that atorvastatin alleviated myocardial fibrosis in db/db mice by regulating the antioxidant stress and anti-inflammatory effects of macrophage polarization on diabetic myocardium, and thereby improving DCM.

Synthetic macrolides overcoming MLSBK-resistant pathogens.

Conventional macrolide-lincosamide-streptogramin B-ketolide (MLSBK) antibiotics are unable to counter the growing challenge of antibiotic resistance that is conferred by the constitutive methylation of rRNA base A2058 or its G2058 mutation, while the presence of unmodified A2058 is crucial for high selectivity of traditional MLSBK in targeting pathogens over human cells. The absence of effective modes of action reinforces the prevailing belief that constitutively antibiotic-resistant Staphylococcus aureus remains impervious to existing macrolides including telithromycin. Here, we report the design and synthesis of a novel series of macrolides, featuring the strategic fusion of ketolide and quinolone moieties. Our effort led to the discovery of two potent compounds, MCX-219 and MCX-190, demonstrating enhanced antibacterial efficacy against a broad spectrum of formidable pathogens, including A2058-methylated Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, and notably, the clinical Mycoplasma pneumoniae isolates harboring A2058G mutations which are implicated in the recent pneumonia outbreak in China. Mechanistic studies reveal that the modified quinolone moiety of MCX-190 establishes a distinctive secondary binding site within the nascent peptide exit tunnel. Structure-activity relationship analysis underscores the importance of this secondary binding, maintained by a sandwich-like π-π stacking interaction and a water-magnesium bridge, for effective engagement with A2058-methylated ribosomes rather than topoisomerases targeted by quinolone antibiotics. Our findings not only highlight MCX-219 and MCX-190 as promising candidates for next-generation MLSBK antibiotics to combat antibiotic resistance, but also pave the way for the future rational design of the class of MLSBK antibiotics, offering a strategic framework to overcome the challenges posed by escalating antibiotic resistance.

Human umbilical cord mesenchymal stem cells derived-exosomes on VEGF-A in hypoxic-induced mice retinal astrocytes and mice model of retinopathy of prematurity.

AIM: To observe the effect of human umbilical cord mesenchymal stem cells (hUCMSCs) secretions on the relevant factors in mouse retinal astrocytes, and to investigate the effect of hUCMSCs on the expression of vascular endothelial growth factor-A (VEGF-A) and to observe the therapeutic effect on the mouse model of retinopathy of prematurity (ROP). METHODS: Cultured hUCMSCs and extracted exosomes from them and then retinal astrocytes were divided into control group and hypoxia group. MTT assay, flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect related indicators. Possible mechanisms by which hUCMSCs exosomes affect VEGF-A expression in hypoxia-induced mouse retinal astrocytes were explored. At last, the efficacy of exosomes of UCMSCs in a mouse ROP model was explored. Graphpad6 was used to comprehensively process data information. RESULTS: The secretion was successfully extracted from the culture supernatant of hUCMSCs by gradient ultracentrifugation. Reactive oxygen species (ROS) and hypoxia inducible factor-1α (HIF-1α) of mice retinal astrocytes under different hypoxia time and the expression level of VEGF-A protein and VEGF-A mRNA increased, and the ROP cell model was established after 6h of hypoxia. The secretions of medium and high concentrations of hUCMSCs can reduce ROS and HIF-1α, the expression levels of VEGF-A protein and VEGF-A mRNA are statistically significant and concentration dependent. Compared with the ROP cell model group, the expression of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signal pathway related factors in the hUCMSCs exocrine group is significantly decreased. The intravitreal injection of the secretions of medium and high concentrations of hUCMSCs can reduce VEGF-A and HIF-1α in ROP model tissues. HE staining shows that the number of retinal neovascularization in ROP mice decreases with the increase of the dose of hUCMSCs secretion. CONCLUSION: In a hypoxia induced mouse retinal astrocyte model, hUCMSCs exosomes are found to effectively reduce the expression of HIF-1α and VEGF-A, which are positively correlated with the concentration of hUCMSCs exosomes. HUCMSCs exosomes can effectively reduce the number of retinal neovascularization and the expression of HIF-1α and VEGF-A proteins in ROP mice, and are positively correlated with drug dosage. Besides, they can reduce the related factors on the PI3K/AKT/mTOR signaling pathway.

Effectiveness of different intrusion modes of maxillary anterior teeth with mini-implants in clear aligner treatment: a three-dimensional finite element analysis.

BACKGROUND: The intrusion of maxillary anterior teeth is often required and there are various intrusion modes with mini-implants in clear aligner treatment. The objective of this study was to evaluate the effectiveness of maxillary anterior teeth intrusion with different intrusion modes, aiming to provide references for precise and safe intrusion movements in clinical practice. METHODS: Cone-beam computed tomography and intraoral optical scanning data of a patient were collected. Finite element models of the maxilla, maxillary dentition, periodontal ligaments (PDLs), clear aligner (CA), attachments, and mini-implants were established. Different intrusion modes of the maxillary anterior teeth were simulated by changing the mini-implant site (between central incisors, between central and lateral incisor, between lateral incisor and canine), loading site (between central incisors, on central incisor, between central and lateral incisor, between lateral incisor and canine), and loading mode (labial loading and labiolingual loading). Ten conditions were generated and intrusive forces of 100 g were applied totally. Then displacement tendency of the maxillary anterior teeth and CA, and stress of the PDLs were analyzed. RESULTS: For the central incisor under condition L14 and for the canine under conditions L11, L13, L23, and L33, the intrusion amount was negative. Under other conditions, the intrusion amount was positive. The labiolingual angulation of maxillary anterior teeth exhibited positive changes under all conditions, with greater changes under linguoincisal loading. The mesiodistal angulation of canine exhibited positive changes under labial loading, while negative changes under linguoincisal loading except for condition L14. CONCLUSIONS: The intrusion amount, labiolingual and mesiodistal angulations of the maxillary anterior teeth were affected by the mini-implant site, loading site, and loading mode. Labial and linguoincisal loading may have opposite effects on the intrusion amount of maxillary anterior teeth and the mesiodistal angulation of canine. The labiolingual angulation of the maxillary incisors would increase under all intrusion modes, with greater increases under linguoincisal loading.

Site-selective S-gem-difluoroallylation of unprotected peptides with 3,3-difluoroallyl sulfonium salts.

Bench-stable 3,3-difluoroallyl sulfonium salts (DFASs), featuring tunable activity and their editable C-ß and gem-difluoroallyl group, proved to be versatile fluoroalkylating reagents for site-selective S-gem-difluoroallylation of cysteine residues in unprotected peptides. The reaction proceeds with high efficiency under mild conditions (ambient temperature and aqueous and weak basic conditions). Various protected/unprotected peptides, especially bioactive peptides, are site-selectively S-gem-difluoroallylated. The newly added gem-difluoroallyl group and other functional groups derived from C-ß of DFASs are poised for ligation with bio-functional groups through click and radical chemistry. This stepwise "doubly orthogonal" modification of peptides enables the construction of bioconjugates with enhanced complexity and functionality. This proof of principle is successfully applied to construct a peptide-saccharide-biotin chimeric bioconjugate, indicating its great potential application in medicinal chemistry and chemical biology.

Synthesis of 2-benzyl N-substituted anilines via imine condensation-isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines.

A catalyst- and additive-free synthesis of 2-benzyl N-substituted anilines from (E)-2-arylidene-3-cyclohexenones and primary amines has been reported. The reaction proceeds smoothly through a sequential imine condensation-isoaromatization pathway, affording a series of synthetically useful aniline derivatives in acceptable to high yields. Mild reaction conditions, no requirement of metal catalysts, operational simplicity and the potential for scale-up production are some of the highlighted advantages of this transformation.

Quantum Criticality with Emergent Symmetry in the Extended Shastry-Sutherland Model.

Motivated by the novel phenomena observed in the layered material SrCu_{2}(BO_{3})_{2}, the Shastry-Sutherland model (SSM) has been extensively studied as the minimal model for SrCu_{2}(BO_{3})_{2}. However, the nature of its quantum phase transition from the plaquette valence-bond solid to antiferromagnetic phase is under fierce debate, posing a challenge to understand the underlying quantum criticality. Via the state-of-the-art tensor network simulations, we study the ground state of the SSM on large-scale size up to 20×20 sites. We identify the continuous transition nature accompanied by an emergent O(4) symmetry between the plaquette valence-bond solid and antiferromagnetic phase, which strongly suggests a deconfined quantum critical point (DQCP). Furthermore, we map out the phase diagram of an extended SSM that can be continuously tuned to the SSM, which demonstrates the same DQCP phenomena along a whole critical line. Our results indicate a compelling scenario for understanding the origin of the proposed proximate DQCP in recent experiments of SrCu_{2}(BO_{3})_{2}.

Different Contributions of embB and ubiA Mutations to Variable Level of Ethambutol Resistance in Mycobacterium tuberculosis Isolates.

Objective: To explore the association between the variant mutations within embB and ubiA, and the degree of ethambutol (EMB) resistance of Mycobacterium tuberculosis (M. tuberculosis) isolates. Methods: A total of 146 M. tuberculosis isolates were used to determine the minimum inhibitory concentrations (MICs) of EMB with a 96-well microplate-based assay. The mutations within embB and ubiA among these isolates were identified with DNA sequencing. Moreover, a multivariate regression model and a computer model were established to assess the effects of mutations on EMB resistance. Results: Our data showed that overall 100 isolates exhibited 28 mutated patterns within the sequenced embB and ubiA. Statistical analysis indicated that embB mutations Met306Val, Met306Ile, Gly406Ala, and Gln497Arg, were strongly associated with EMB resistance. Of these mutations, Met306Val and Gln497Arg were significantly associated with high-level EMB resistance. Almost all multiple mutations occurred in high-level EMB-resistant isolates. Although the mutation within ubiA accompanied with embB mutation presented exclusively in EMB-resistant isolates, four single ubiA mutations (Ala39Glu, Ser173Ala, Trp175Cys, and Val283Leu) leading to protein instability were observed in EMB-susceptible isolates. Conclusion: This study highlighted the complexity of EMB resistance. Some individual mutations and multiple mutations within embB and ubiA contributed to the different levels of EMB resistance.

Changes of intestinal barrier in the process of intestinal inflammation induced by Aeromonas hydrophila in snakehead (Channa argus).

Bacterial intestinal inflammation frequently occurs in cultured fish. Nevertheless, research on intestinal barrier dysfunction in the process of intestinal inflammation is deficient. In this study, we explored the changes of intestinal inflammation induced by Aeromonas hydrophila (A. hydrophila) in snakehead and the relationship between intestinal barrier and inflammation. Snakehead [(13.05 ± 2.39) g] were infected via anus with A. hydrophila. Specimens were collected for analysis at 0, 1, 3, 7 and 21 d post-injection. The results showed that with the increase of exposure time, the hindgut underwent stages of normal function, damage, damage deterioration, repair and recovery. Relative to 0 d, the levels of IL-1ß and TNF-α in serum, and the expression of nod1, tlr1, tlr5, nf-κb, tnf-α and il-1ß in intestine were significantly increased, and showed an upward then downward pattern over time. However, the expression of tlr2 and il-10 were markedly decreased, and showed the opposite trend. In addition, with the development of intestinal inflammation, the diversity and richness of species, and the levels of phylum and genus in intestine were obviously altered. The levels of trypsin, LPS, AMS, T-SOD, CAT, GPx, AKP, LZM and C3 in intestine were markedly reduced, and displayed a trend of first decreasing and then rebounding. The ultrastructure observation showed that the microvilli and tight junction structure of intestinal epithelial cells experienced normal function initially, then damage, and finally recovery over time. The expression of claudin-3 and zo-1 in intestine were significantly decreased, and showed a trend of first decreasing and then rebounding. Conversely, the expression of mhc-i, igm, igt and pigr in intestine were markedly increased, and displayed a trend of increasing first and then decreasing. The above results revealed the changes in intestinal barrier during the occurrence and development of intestinal inflammation, which provided a theoretical basis for explaining the relationship between the two.

Extracellular vesicle surface display enhances the therapeutic efficacy and safety profile of cancer immunotherapy.

Immunotherapy has emerged as a mainstay in cancer therapy, yet its efficacy is constrained by the risk of immune-related adverse events. In this study, we present a nanoparticle-based delivery system that enhances the therapeutic efficacy of immunomodulatory ligands while concurrently limiting systemic toxicity. We demonstrate that extracellular vesicles (EVs), lipid bilayer enclosed particles released by cells, can be efficiently engineered via inverse electron demand Diels-Alder (iEDDA)-mediated conjugation to display multiple immunomodulatory ligands on their surface. Display of immunomodulatory ligands on the EV surface conferred substantial enhancements in signaling efficacy, particularly for tumor necrosis factor receptor superfamily (TNFRSF) agonists, where the EV surface display served as an alternative FcγR-independent approach to induce ligand multimerization and efficient receptor crosslinking. EVs displaying a complementary combination of immunotherapeutic ligands were able to shift the tumor immune milieu toward an anti-tumorigenic phenotype and significantly suppress tumor burden and increase survival in multiple models of metastatic cancer to a greater extent than an equivalent dose of free ligands. In summary, we present an EV-based delivery platform for cancer immunotherapeutic ligands that facilitates superior anti-tumor responses at significantly lower doses with fewer side effects than is possible with conventional delivery approaches.